Furniture



Aug. 6, 1957 c. G. LAMBERT FURNITURE Filed Sept. 18, 1952 IN VEN TOR.farfzi (LZQ/ze/ United States Patent O 1 2,801,633 FURNITURE CharlesGordon Lambert, North Manchester, ind, as-

signor to The Peabody Seating Company, lino, North Manchester, End, acorporation of Indiana Application September 13, 1952, Serial No.31%,269 4 Claims. ('Ci. 155 194) My invention relates to furniture andincludes among its objects and advantages an increase in lightness andstrength in steel members for furniture.

In the accompanying drawing:

Figure 1 is a perspective view of a folding chair;

Figure 2 is a fragmentary side view of one of the long leg members;

Figure 3 is a view, as in section on line 3-3 of Figure 2, showing thereinforcing insert in end view;

Figure 4 is a transverse section of a modified construction; and

Figure 5 is a detail on line 5--5 of Figure 2.

in the embodiment of the invention selected for illustration, theinvention is incorporated in a conventional folding chair. Thiscomprises long leg members and 12, extending up to form the side membersof the back, above the seat 14. The upper ends of the leg members areunited by a curved bight 16, and the panel 18 set into the bightcompletes the back structure. The rear legs 20 and 22 are pivoted attheir upper ends at 24 and 26 to the back leg members 10 and 12 abovethe level of the seat 14. The seat itself is pivoted to the leg members10 and 12 at 28 and 3d. The rear legs are crossbraced a short distanceabove the floor level by a crosspiece 32, and the front legs aresimilarly braced by a cross-piece 34.

Each of the leg members is a tube formed from a flat piece of sheetmetal by curving it into the shape indicated in Figures 3 and 4. In onecommon size, such a leg is one inch in its major cross-sectionaldimension, and three-quarters of an inch in a direction at right anglesthereto. It includes the narrow portion 36 of relatively large radius ofcurvature, the lobes 38 and 4'0, and the turned-in edges 52 and 44 inthe center of the relatively flat portion opposite the portion 36; theseedges are not welded or otherwise united with each other, except thatadjacent cross-brace 34, and adjacent the pivot 46 for the seat 14, theyare cut away to receive the parts 34 and 36, and all the parts are thenwelded or brazed where they pass through, as indicated in Figures 2 and3, by the lump of Weld metal at 48 around the pivot 46 and a lump 5%?around the cross-brace 34. Both the cross-brace 34 and the pivot 4-6 goon through the back of the leg structure and are riveted over on theoutside as indicated in Figures 3 and 4 by the head 52.

The point of maximum bending load in such a leg is adjacent the pivot46, but users not infrequently engage the cross-brace 34 with their feetso that impact is likely to be received at that level. I have found thata great increase in strength and durability under load is obtainable oymeans of a G-shaped insert 54, which fits snugly inside each of the legs10 and 12, and extends about three-quarters of an inch below the brace34, and about an inch and one half above the pivot 46. Such a relativelyopen r'J-shaped tube can be fashioned from thin sheet metal in the sameway that the leg itself is fashioned. If it is originally formed of asize so that it can slide into place inside the leg, under a thrust of ahundred pounds or so, the resulting assembly, as indicated in Figure 3,loes not have an absolutely perfect and continuous contact between thesleeve 54 and the leg. In Figure 3 l have indicated three short portionsat 56, 58, and 60, where the inner layer of metal does not remain inperfect Contact with the leg, and a slight clearance remains.

Referring now to Figure 4, if the insert 54 is originally "ice fashionedso that its undistorted shape before insertion is as indicated by thedotted line position, from three to ten times as much axial thrust maybe necessary to make the assembly, and the corners of the metal at endinserted first should be twisted in about a sixteenth of an inch, with apair of pliers or by impact, to help get started. By this method ofassembly, it is possible to eliminate substantially all clearancebetween the leg and its reinforcing insert, and a minor fraction ofadditional mechanical strength under load is obtainable.

A satisfactory diameter for the pivot. 46 is one-quarter inch. The pivotmay be of uniform diameter throughout, indicated in Figure 3. Asatisfactory diameter for the cross-brace 34 is three-eighths inch. Theadditional material is needed because this member frequently carries abending load. The extreme end of rod 34 is reduced in diameter, asindicated at 62 in Figure 5, so that the rivet head 52 grips both layersof sheet metal positively. The liner 5'4 is firmly anchored againstlongitudinal movement by both members 34 and 46, but the most completeclamping action is adjacent the member 34, remote from the point ofmaximum bending load at 46, so that the metal at 46 has a minimum oflocal residual stresses caused by the operation of assembly.

Others may readily adapt the invention for use under various conditionsof service, by employing one or more of the novel features disclosed, orequivalents thereof. As at present advised, with respect to the apparentscope of my invention, I desire to claim the following subject matter.

I claim:

1. A structural member suitable for chair legs and similar uses, subjectto compound loads, comprising, in combination: a single piece of sheetmetal bent to form an outer tube, with the opposite longitudinal edgesof the piece adjacent each other; said tube edges being turned inwardlyto define stiffening flanges; and a onepiece sheet metal reinforcingliner also bent to form a tube; the liner edges being spaced apart toleave clearance for said inwardly turned tube flanges; said linerfitting snugly against the inner wall of said outer tube.

2. A member according to claim 1 in. which the crosssection of saidouter tube is an oblate circle having its maximum transverse dimensionin a plane perpendicular to r a median plane passing between saidinwardly-turned outer tube edges.

3. A member according to claim 1 in. which said liner in undistortedcondition is too large to fit inside said outer tube and is slightlycompressed within said outer tube, whereby both tubes are under a lightpermanent stress to hold them in firm contact.

4. A member according to claim 1 in combination with a transversestructural connecting rod intersecting the member and perpendicularthereto; said rod having its axis in a median plane of the memberpassing between said inturned flanges; said rod penetrating the memberand liner at a point diametrically opposite said inturned flanges andanchoring said outer tube andliner against relative longitudinalmovement.

References Cited in the file of this patent UNITED STATES PATENTS1,661,580 Scholl Mar. 6, 1928 1,730,916 Cable Oct. 8, 1929 1,958,042Hanson May 8, 1934 1,982,868 Herold Dec. 4, 1934 2,039,824 Morgan et a1.May 5, 1936 2,177,186 Nordmark Oct. 24, 1939 2,620,019 Merrill et a1.Dec. 2, 1952 FOREIGN PATENTS 30,341 Australia Sept. 17, 1931

